Various types of semiconductor laser diodes are used in a variety of industrial and scientific applications. A distributed feedback (DFB) laser, for example, is one type of laser diode where the active region of the device is periodically structured as a diffraction grating to provide lasing at a particular wavelength or range of wavelengths. Lasers diodes, such as DFB lasers, may be used, for example, in optical transmitters or transceivers for telecommunications applications. In some of these applications, a laser diode chip is mounted on a sub-mount including a substrate with conductive material for providing electrical connections to the laser diode, commonly called a chip-on-submount (COS) package. A COS package may be installed in another package or assembly, such as a butterfly laser package or a transmitter optical subassembly (TOSA). In other applications, a plurality of laser diodes may be formed together as a bar, commonly referred to as a bar laser.
Laser diodes are tested to ensure the operating parameters and overall quality of the laser diodes. These tests are generally performed before assembling the laser diode into another package or assembly during manufacturing. The testing often includes performing optical power measurements such as light-current-voltage measurements and wavelength measurements such as side-mode suppression ratio (SMSR) and peak wavelength measurements. Because of the challenges involved with measuring distinct parameters, such as optical power and wavelength, different testing procedures are performed separately to reliably measure these different parameters. Performing multiple separate testing procedures on each laser diode may slow the manufacturing process, especially when the tests must be performed on each of a number of laser diodes.